Font Size: 

In this work the dynamic instability of imperfect simply supported viscoelastic circular cylindrical shells subjected to internal flowing fluid and lateral harmonic loads is studied. Donnell’s non-linear shallow shell theory is used to model the shell, assumed to be made of a Kelvin-Voigt material type and the linear potential theory is used to describe the effect of the internal axially flowing fluid. The fluid is assumed to be incompressible and non-viscous and the flow to be isentropic and irrotational.
A modal solution with eight degrees of freedom which takes into account the essential modal couplings and interactions is used to describe the lateral displacements of the shell. The Galerkin method is applied to derive a set of coupled non-linear ordinary differential equations of motion that are, in turn, solved by the Runge-Kutta method. Continuation techniques are used to study the influence of shell geometry, flow velocity and dissipation parameter and special attention is given to resonance curves and bifurcation diagrams. Obtained results show that geometric initial imperfections together with the viscoelastic dissipation parameter and internal fluid have significant influence on the dynamic instability of the cylindrical shells.